Madonna works out for 'five hours a day'

Madonna works out for "five hours a day", according to SoulCycle Master Instructor Stacey Griffith.

The 58-year-old pop megastar is determined to keep her body in shape, so much so that she hits the gym for the impressive timescale every single day.

SoulCycle Master Instructor Stacey Griffith - who has trained the 'Vogue' hitmaker in the past - revealed: "Pro athletes train all day. Madonna trains all day. She trains for five hours a day, non-stop."

And Stacey admitted training with stars like Madonna is "surreal", and she often has to take a moment to comprehend what is happening when working with celebrities.

She told Kelly Ripa during a Q&A in New York City for her new book 'Two Turns From Zero' - which hit shelves on Tuesday: "It's surreal ... those moments when I think about moments in my life that I would want to have happen and I do my visualisations in my own way, in my own special way in my office. I do my meditations and my mantras, and one day I was in the room doing a private, just me at like 3:30 in the afternoon. Music playing. It's me, Madonna and Craig, her trainer.

"I'm like 'Hang on a second, Stacey. You're training Madonna. Just sit in it for a second.'"

And it's not just Madonna - who has children Lourdes, 20, Rocco, 16, adopted children David and Mercy, both 11, and four-year-old adopted twins Esther and Stella - who has found sporting success in her family either, as her daughter Mercy recently won four medals at a gymnastics tournament.

Madonna took to her Instagram account to share a snap of her daughter complete with her four medals, adding the caption: "Mercy James takes home 4 Medals! (sic)"

The 'Hung Up' hitmaker also posted a picture of Mercy and some of her team-mates standing on a podium celebrating their success with their hands clasped together while up in the air.